EMERGENCY: The critical condition of hospital power
On April 16, 2002, Rhode Island Hospital and Women & Infants Hospital lost power for an afternoon, leaving various parts of the 33-building campus dark for varying amounts of time. Though no one part of the hospital ever completely went black, the outage threw the operating-room schedule into disarray, postponing procedures and jeopardizing patient health.
Power was restored to the campus that afternoon, an hour and 20 minutes after the failure. At Women & Infants, an emergency generator immediately turned on, emergency lights came on, and no essential services were disrupted, according to a Providence Journal article. However, at Rhode Island Hospital, the backup electric system did not work, prompting Providence Mayor Vincent A. Cianci Jr., to tell the Providence Journal, “A hospital of this magnitude and this size should not have these problems.”
Surprisingly, power outages do happen with alarming frequency to big hospitals. In fact, they’ve happened at Rhode Island Hospital campus before. In September 1999, a blackout plunged the entire campus into darkness. The backup systems failed once again and this time a patient died after his respirator failed.
Then, in January 2000, another power failure forced the hospital to rely on backup generators for nearly two hours and shut down nonessential equipment and lights. A faulty ceramic insulator at a substation on the hospital campus caused the failure. Then a damaged coil prevented some of the backup power from flowing back into one of the hospital buildings.
Power outages happen at bigger hospitals in bigger cities, too—sometimes for longer periods. In July 1999 Hurricane Floyd blew through New York City, causing a blackout that stopped full electrical service at Columbia-Presbyterian Hospital for three days. ConEdison, New York City’s electrical utility, asked Columbia-Presbyterian to use emergency generators to help lessen demand for ConEd Power, leaving Columbia-Presbyterian with emergency generator power for critical equipment only. The outage begged the question: Is this ConEd’s fault, or should this hospital (and every other hospital) have made better provision to protect their power?
After its 1999 power failure, the Rhode Island Hospital conducted a full analysis of the electrical system and implemented a corrective-action plan that included an $11-million upgrade to the electrical system. The hospital purchased a large diesel generator as a third level of backup.
THE THREE-SECOND LAG
As plentiful and redundant as tertiary backup power sounds, diesel generators alone simply can’t provide failsafe backup power to protect hospital patient. That’s because the transitional lag between utility and generator power time throws computerized diagnostic and life-support equipment out of whack. Even a three-second disruption can be perilous to sensitive electronic equipment.
Further, some Uninterrupible Power Systems (UPS) manufacturer studies claim that, on average, emergency generators—for a variety of reasons that mostly involve human error—start only 90% of the time during a power failure. That’s why healthcare facility standards require emergency generators to be tested diligently. That’s also why, budgets permitting, electrical engineers and contractors like to specify UPSs to protect vital equipment from disruptions.
“It makes perfect sense to use diesel generators as a back-up,” said Joergen Peter Madsen, Sr., Product Manager, ESSG, American Power Conversion, a manufacturer of Uninterruptible Power Systems, based in West Kingston, R.I. “Rhode Island Hospital should be a very safe system.” The hospital has their own power plant with steam generators, co-generating with utility power. "They can run entirely from their own plant, or from utility power," he said. "They also have a diesel generator, which is required if the local power plant has to start up from scratch, without utility power. On top of this, critical loads are protected by UPSs. Human error caused the last incident at Rhode Island Hospital. I seem to remember it happened during a transfer from one feed to another.”
Madsen said that a number of hospitals use diesel generators as backup but also protect critical loads with UPSs. He said UPSs can “fill the small gap” for the critical loads between the time the utility fails and the generators are powered up. “When the diesels are running you are good to go as long as you can get diesel for the generators.
Mark Miller is a Class II electrician at Montgomery General Hospital, Montgomery, W. Va., a small college town with a mid-sized hospital. The hospital maintains five separate substations, all at 12480V, and two emergency generators—-one rated for 500kVA, the other for 250kVA. “Both generators are old, but very reliable,” Miller said.
“We have had two outages since I have been here, and the generators have worked great,” Miller said. “One outage came during a terrible snow/hail storm. After the generators came on, we discovered the ICU had no re-circulating air fans (critical to the removal of airborne diseases). Going to the roof, we discovered high winds had literally ripped the hoods from both fans (6ft by 6ft sq fiberglass) and drove them into the motors, destroying both. We removed debris and changed those two motors that night. Whew!
“The second Montgomery power outage knocked out a transformer station that supplied power to one of the chiller/tower units and the CT scanner units. The generators came through until we could reassign power supplies during the transformer replacement, which was performed superbly by Siemens/Westinghouse. They shipped us a new transformer and placed it on the roof with a crane. Five of their crew plus myself installed it and we fired the new one up just 26 hours after the failure,” Miller said.
WHY POWER PROBLEMS PLAGUE HOSPITALS
Power problems plague hospitals much more frequently than they do other high-tech facilities—such as banks, data centers and clean-room manufacturing facilities. Financial institutions invest millions in power protection because the slightest power dip or sag can damage sensitive computers, causing millions in lost revenue.
Hospitals don’t spend nearly as much on emergency power protection as banks do because they don’t have the budget. Accountants don’t consider absolutely fail-safe 24/7 power for hospitals “cost-effective.” In fact, power-quality professionals seldom talk about the ultimate 99.999% level (“five nines”) of reliability outside of the financial database arena. “Five Nines” translates roughly into only 3 seconds of power downtime per year. Ironically, when hospitals do spend big money on power protection, it’s to protect their critical data systems, not their critical-care systems.
Besides money, regulations also pose another potential stumbling block to hospital power protection. No standards-issuing agency requires any industry to buy sophisticated emergency power backup systems. It’s simply a matter of economics: High-tech data centers purchase power-protection equipment, based on the free-market value of computer downtime. Hospitals use diesel generators for emergency backup power. Agencies, ranging from The National Fire Protection Association (NFPA) to the Joint Commission on Accreditation of Healthcare Organizations (JCAHCO), mandate that virtually all hospitals backup up utility power with emergency diesel generators. JCAHCO requires that hospitals regularly test emergency generator systems, but doesn’t address the transitional gap between utility and generator power.
The NFPA 110, Chapter 6, “Maintenance and Testing,” provides detailed regulations for backup generator testing and maintenance in healthcare facilities. Meanwhile, the National Electrical Code (NEC), Article 517, Health Care Facilities, mandates stringent electrical requirements in healthcare facilities. The NEC stresses GFCI grounding protection, critical branch transfer switches, tamper-resistant receptacles and surge-suppression. But the NEC’s authority seems to end with power supply.
HOSPITAL TALES FROM THE LIGHT AND DARK SIDES
Electronics have changed everything. Hospital operating rooms no longer resemble “M*A*S*H” episodes, where power goes out after bombshell blasts nearby and then the backup generator kicks on 10 seconds later so everyone can get right back to work. Today, even a momentary power interruption can damage electronic patient-care equipment. Unfortunately, hospital rooms aren’t quite as high-tech “Star Trek” yet either. Medical science hasn’t yet invented small handheld, battery operated instruments that can completely diagnose a patient’s health. Everything needs to be plugged in.
Still, power disruptions that last longer than 10 seconds are rare at hospitals these days because generators generally will switch on when they’re needed. MacDill Air Force Base hospital in Central Florida is a typical case. The hospital uses two 350kW generators to provide emergency backup power for the entire facility. The Florida branch of Del-Jen, a national service maintenance firm, based in Rolling Estates, Calif., services the generators. An automatic paralleling switch controls two 350Kw generators and two 800A transfer switches.
In the event of a commercial power outage, both of MacDill’s auto-start switches call for a generator start through the paralleling switchgear. The first generator that comes up to speed is placed on line by the paralleling switchgear and the critical bus auto-start switchgear switches to generator power. The paralleling switchgear adjusts frequency and voltage on the second generator and then “parallels” it with the generator already on line. The switchgear makes the utility auto-start switchgear switch to the generator. This whole operation happens within 7 seconds. If for any reason one of the generators fail, the paralleling switchgear will open the utility auto-transfer switch to prevent over-loading of one generator.
The Del-Jen power-production shop team tests the systems weekly under no-load once a month under building load. Units are serviced every six months. MacDill AFB electrical supervisor Dan Gress said MacDill has never had any major problems with their generators. “We service the generators and have never experience any outage that caused harm to equipment or people.”
Hospitals like MacDill often buy UPS systems to provide isolation protection for sensitive diagnostic equipment that can be damaged during the lag three-second outage. Without UPS protection, even when emergency generators do kick on properly after an outage, doctors and nurses still scramble to ensure that all the critical life-support equipment has responded properly and reset, restarted or recalculated.
Montgomery’s Mark Miller said that his hospital employs UPSs to protect sensitive equipment. “Some of the manufacturers provide them with the diagnostic equipment the hospital purchases.”
Miller has also proposed flywheel UPSs, power monitoring systems, phase-loss monitors and power quality systems.
“I understand, though, that no matter how important electrical systems might be, it has to fit within a hospital’s budget. There is no cheap hospital equipment and I have been fortunate, though, that our hospital administration has a good ear, and we have seen some improvements that we have requested.”
With the increasing computerization of patient care, hospitals are starting to see their reliable power shortcomings and many are taking action to improve their power protection. The best solutions include fuels cells, flywheel UPS systems, emergency power-monitoring systems.
CASE STUDY: THE FLYWHEEL SOLUTION
According to Caterpillar, a Peoria, Ill.-based manufacturer of generator sets, the slightest interruption of power can leave a hospital in a very critical position. Without power to ride-through those crucial seconds of an outage until the emergency generator comes on-line, high-tech healthcare equipment is vulnerable to software or hardware damage.
Caterpillar now offers its Cat UPS to work in conjunction with generators. Ranging in power from 300 kVA to 900 kVA, the battery-free UPS integrates flywheel technology that protects against sags, surges and outages. The system uses stored-energy flywheel technology, which Caterpillar says is more reliable and less costly than conventional battery UPSs. The Cat UPS provides power conditioning and supplies power in the transition period between a failure and generator startup.
Rebsamen Medical Center, Jacksonville, Ark., recently installed this flywheel UPS.
“Power in central Arkansas can be unstable,” said Ed Meharg, director of engineering for Rebsamen. “We experience numerous power failures, from a fraction of a second to several hours. Even a short power glitch can wreak havoc on our sensitive diagnostic medical equipment.” The acute-care facility is particularly concerned about protecting the sophisticated, MRI and CAT Scan equipment it recently purchased.
Meanwhile, UPS manufacturer Active Power now offers its Powerware flywheel UPS. The system recently was installed at Fairview Hospital, a 478-bed acute-care facility on the western edge of Cleveland.
“It’s a green solution, said Paul Slebodnik, director of facilities management at Fairview. “It extends the life of lead-acid batteries, reducing the need for frequent handling and the disposal of hazardous waste. The flywheel brings a greater degree of reliability to our critical power systems,” said Slebodnik. “The decision to install a flywheel system was in part based on a five-year cost analysis. We looked at the cost of the flywheel, the cost of buying batteries, the disposal of the batteries, and the risk and cost of downtime, maintenance and reliability,” said Slebodnik.
“We take regular hits from the utility company,” said Ernie Frick, compliance manager at Fairview Frick. “Now, the flywheel takes the hits without ever even crossing the batteries.” Frick said the hospital performs monthly generator tests, where power is transferred from ‘normal mode’ to ‘emergency.’ “Here too, the flywheel takes the transfer rather than the batteries,” he said. As a result, Frick said they are actually extending battery life.
The hospital’s diesel backup generator starts within 10 seconds, Slebodnik said. The flywheel provides support for 15 to 120 seconds.” It takes a progressive institution to take the long-term view, in terms of the reliability benefit, potential lost revenue from downtime, and the benefit to patient care,” Slebodnik said.
CASE STUDY: AN AUTOMATED GENERATOR-TESTING SOLUTION
As previously mentioned, JCAHCO requires that hospitals regularly test emergency generator systems for protection against utility disruptions. Generator testing can be an arduous task, involving manual switching, testing and recording of generator test results. To automate this task manufacturer, Square D, developed its Powerlogic power monitoring system.
The operations staff at the Veteran Affairs Medical Center in Nashville, Tenn., recently installed the system as part of a $3 million dollar electrical system improvement project. Using the system, Herschel Flannery, the VA’s electrical engineer, monitors the hospital’s Emergency Power Supply System (EPSS) and recently upgraded electrical system. The power-monitoring system automates the generator-testing sequence in order to document compliance with minimum loading criteria throughout the test cycle.
Built in the mid-1960s, the hospital has a 480Y/277V electrical service from four network-connected 1000 KVA transformers. The network transformers, owned and maintained by the Nashville Electric Service (NES), were fed from 2 NES 13.8 kV feeders. The transformer network provided reliable power for more than 30 years, but it was old, fully loaded and land-locked in an inaccessible vault. Concerns about future growth and the possibility of a transformer failure prompted the VA to budget $3 million to replace transformers, service, service switchboards and other old and obsolete distribution equipment.
Nashville-based engineering firm Nash Lipsey Burch advised the hospital that replacing the “spot network” service with a conventional service–even a dual 480V double-end service–would be unsatisfactory to the medical staff. NES, however, no longer provided network transformers to its customers. With the VA’s approval, Nash Lipsey Burch designed two new spot networks, each consisting of two 2,000 KVA transformers owned by the VA. Network protection for each spot network is provided by two 2,500A solid-state microprocessor trip circuit breakers equipped with directional current relays and a ground-fault scheme that totalizes zero-sequence currents flowing through the two mains. The two spot networks feed opposite ends of a double-ended 5,000A switchboard, providing additional redundancy.
“Since commissioning the power monitoring system, we have found that we do a more efficient job of testing,” said Mike Hurst, the VA’s chief electrician. Since the system continuously monitors kW loading throughout generator testing, the VA is confident that the hospital is fully complying with the JCAHO EC 2.10.4.1 loading requirements, adequately exercising their EPSS (Electronic Performance Support Systems) and verifying its readiness for a power outage.
FUEL CELLS, THE FINAL SOLUTION
Fuel cell power seems to be an ideal solution to hospitals and other facilities in which power reliability is crucial. Fuel cells, which generate electricity from a hydrocarbon fuel such as natural gas, propane or diesel, have been touted in the press for the last few years as the most promising of long-term power technologies for the future.
So far, one particularly promising firm has been FuelCell Energy Inc. The company, which manufacturers molten carbonate fuel cell (MCFCs) systems that target the larger-scale distributed generation market, has developed a patented fuel cell called the Direct FuelCell (DFC). In April 2002, Fuel Cell Energy teamed with to sell Direct FuelCell (DFC) power plants throughout North America, and the development of Caterpillar-branded fuel-cell power plants.
Meanwhile, Siemens Westinghouse Power Generation has developed tubular solid-oxide fuel cell technology as part of the U.S. Department of Energy’s advanced fuel-cell research program, which is managed by DOE’s Office of Fossil Energy and overseen by its National Energy Technology Laboratory in Morgantown, W. Va. Siemens Westinghouse has formed the Stationary Fuel Cells Div., dedicated to completing the “commercialization” of solid-oxide fuel cells. A new factory to produce this new distributed generation technology is under construction in Pittsburgh, Pa.
Though many still think of fuel cells as a futurist pipe dream, the technology has already proven successful in some large-scale applications. In December 2000, North Central Bronx Hospital (NCBH) became one of the first medical facilities in the country to generate electricity from a fuel cell power plant.
“This project demonstrates the suitability of this cutting-edge technology for institutions like hospitals that have zero tolerance for power glitches,” said C.D. “Rapp” Rappleyea, chairman and chief executive officer of the New York Power Authority (NYPA), which financed and installed the fuel cell. “We think fuel cells will play an important role in the future—not only in terms of reliable power, but in providing an environmentally benign alternative to traditional sources of power.”
The NYPA’s $900,000 fuel cell, co-funded with a $200,000 grant from the U.S. Department of Energy (USDOE), supplemented the electricity the hospital ordinarily receives from the electric power grid. So far, the fuel cell has worked error-free, demonstrating the ability to provide backup power, in addition to the medical facility’s emergency diesel generators, in the event of problems with the electric grid.
The 200-kW fuel cell is the third in a series of such units that NYPA has installed for public facilities in New York City and Westchester County. The other two—also co-funded by the USDOE—are at the Central Park Police Precinct in Manhattan and the Westchester County Wastewater Treatment Plant in Yonkers.
The North Central Bronx Hospital uses natural gas to produce electricity. Hydrogen obtained from the fuel combines with oxygen in the air to produce the power, with the only emissions being water and heat.
“It’s difficult to place a price tag on the benefits of having this clean and dependable source of electricity for the hospital’s diverse power needs “ said Joseph S. Orlando, senior vice president, North Bronx Healthcare Network, consisting of NCBH, Jacobi Medical Center and five community health centers.
“Obviously, it’s essential for us to have uninterrupted power for our operating and emergency rooms, medical equipment and computers. Our patients’ lives depend on it, and this fuel cell will help to ensure they have it.”
Mark Miller’s generator maintenance
Following is the generator maintenance schedule Mark Miller practices for Montgomery General Hospital, Montgomery, W.Va.
“I do a visual check on the generators every morning and every Friday I run them both. Once a month during these Friday runs, I will put them online and operate the hospital on them for about an hour. I record how long they take to come online, how long they take to switch back, engine vitals, etc. On the other Fridays I operate them off-line for about 40 minutes, using a load generator that simulates up to 250kVA of load. And they do use parallel switching. Every time I run the generators, I am required to log the date, time and all pertinent information and it must be up-to-date and available to our hospital administration whenever needed.”
Both generators come online simultaneously, usually within two to three seconds of an outage. Once the outage is over, one generator usually switches back within about three minutes; the other takes about four minutes.
A healthcare emergency power course
A publication from the Motor and Generator Institute and Healthcare Circuit News provides information on how to comply with various healthcare facility standards, including JCAHO, CMS (Children’s Medical Services, State and NFPA 110, Chapter 6, "Maintenance and Testing" referred to in JCAHO, EC 2.10.4.1. The publication qualifies as a Certificate Correspondence Course for American Hospital Association's Certified Healthcare Facility Manager (CHFM) credential renewal. An award of six "contact hours" will be made upon successful completion. Content Code 3; Type Code 3
The course is designed to stay abreast of the latest codes and standards changes as they relate to the EES (Essential Electrical Systems) in general and the EPSS (Electronic Performance Support Systems). It provides an in-depth look at NFPA 110, and can help prevent Type 1 recommendations and write-ups for non-compliance to Utility Management Codes. For more information, visit Healthcare Circuit News at http://www.mgi-hcn.com/.
Ground fault--a medical emergency
The following “true-life example from a metropolitan hospital” is excerpted from “Uptime all the time, designing a safe and reliable electrical system, Part 1. Source: Buildings.com
A hospital added a new wing to its existing 30-year-old facility. A power system study performed on the new electrical distribution system only assured coordination between protective devices within the new system. The new electrical system consisted of a 4160V switchgear, 4160V primary/480V secondary substations, 480V and 208V panelboards, and 480V and 208V motor control centers (MCC). The contract for the power system study did not include the existing electrical system in the study.
At 1:25 a.m. on Oct. 3, 1998, a ground fault occurred in a 25 hp fan motor supplied from a motor control center located on the second floor of the existing building. The protective device in the motor control center did not trip, nor did it trip the upstream feeder circuit beaker that supplied this MCC via an automatic transfer switch (ATS). The main breaker for the existing power center thus operated and removed power from the faulted system. This resulted in a loss of power to half of the existing facility. All power was lost to the critical care loads, including life support and patient isolation ventilation systems.
Subsequent to the main circuit breaker trip, all automatic transfer switches sensed the loss of power. A signal was sent to start the emergency generators. Once the generators started, the automatic transfer switches operated and re-established a supply of power to the emergency system. The emergency power was not supplied for long since the ground fault was still present at the 25hp fan. The circuit breaker on the emergency system feeding all the transfer switches tripped, resulting in the complete loss of power to the hospital.
Fortunately, the medical staff, trained for this type of emergency, reacted without delay. Several patients on respirators were in severe danger of suffocating. The medical staff manually operated bag valve masks that breathed for the patients. After 20 minutes, the fault was isolated and power was restored with no harm to any patients.